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Module Netamqp_connection

module Netamqp_connection: sig .. end
Manage AMQP connections

A connection on the AMQP level is a managed version of the transport stream (i.e. the TCP connection). There is a handshake at connection establishment time where protocol details are negotiated and the client is authenticated.

There is another handshake at connection close time where one peer initiates the closure and the other peer has to approve. Either peer can initiate closure. It is possible to transmit error codes at connection close time.

The transport stream is automatically closed when the close handshake has finished.

In this implementation, connection management is separated from endpoint management. The latter is done in Netamqp_endpoint, and describes the AMQP client on a lower level.

exception Not_open
Raised if the connection is not known to be open on the client side
exception Error of string
An error occurred in connection management
type connection 
The connection management object
type auth_method 
An authentication method, including client identity and credentials
type locale_preference = [ `Pref of string | `Select of string list -> string ] 
One can select the locale for error messages coming from the server:
  • `Pref p: Prefer the locale p if possible, otherwise choose the first locale offered by the server
  • `Select f: Call the function f with all possibilities to select the locale.
Locales are identified as in Unix, e.g. "en_US".
val create : Netamqp_endpoint.endpoint -> connection
Create the connection management object for the endpoint. The endpoint should be in `Off state. The returned connection object is still closed, and may now be opened.
val open_e : connection ->
auth_method list ->
locale_preference -> string -> unit Uq_engines.engine
Opens a connection: The endpoint is instructed to connect on the transport level, to negotiate protocol parameters, and to authenticate the client.

The string argument is the virtual host of the AMQP server to connect to, e.g. "/".

val open_s : connection ->
auth_method list ->
locale_preference -> string -> unit
Same as synchronous function
val close_e : connection -> unit Uq_engines.engine
val close_s : connection -> unit
Request client side closure.
val is_open : connection -> bool
The connection is first open after the open handshake has been completed, i.e. when open_e or open_s are done.

Note that the peer can close channels at any time, so there is no guarantee that the channel is still open when is_open returns true.

Checking is_open is mainly useful for recovery after exceptions. Some exceptions close the channel, some do not.

val plain_auth : string -> string -> auth_method
plain_auth username password: use PLAIN authentication.

Note that username and password are not encrypted on the wire!

val endpoint : connection -> Netamqp_endpoint.endpoint
Return the endpoint the connection uses
val event_system : connection -> Unixqueue.event_system
Return the event system the connection uses
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